Contact pickups are commonly used in connection with stringed musical instruments, especially in the bridge of electrically amplified acoustic guitars. The most versatile configuration for a bridge pickup is that which produces independent string signals. This allows the sound of each string to be individually processed and also allows the instrument thus monitored to control a second instrument such as a music synthesizer.
U.S. Pat. No. 3,453,920 issued to Scherer exemplifies a contact pickup for an instrument string in which the string support is fixed to and supported by two transducer elements disposed to respond respectively to different planes of vibration.
A first problem exists in such a pickup when the transducer elements do not lie in a common plane, that the bottom faces of the string support must mate well with the contacting faces of the supporting transducer elements in order to distribute the applied pressures evenly over the entire area of both transducer elements. Since it is not preferable to have thick bond lines between the parts for reasons of solidity as well as transduction preformance, this configuration imposes strict dimensional and angular tolerances upon the parts comprising the assembly, which tends to increase the cost of manufacture of such a pickup.
A second problem exists in such an arrangement of parts, that when the vibrating string applies pressure to one transducer element, it must also exert shear forces on the other element. This reduces the transduction efficiency of the pickup especially when the transducer elements are relatively compliant or when the string support is made of a very hard and unyelding material.
It is therefore a broad object of the present invention to provide a pickup for an instrument string having multiple transducer elements responding maximally in different planes of vibration and in which the shear forces applied to the transducer elements by the string vibrations are significantly reduced.
It is a more specific object of the present invention to provide a pickup having high sensitivity in virtually all planes of vibration of the contacting string.
It is a further object of the present invention to provide a pickup having the above-mentioned enhancements and which is more economical to manufacture than corresponding pickups in the prior art.